Feed roll for stamp vending machines



June 30, 1959 zElGLE FEED ROLL FOR STAMP VENDING MACHINES 2 Sheets-Sheet 1 Filed Dec. 6, 1954 June 1959 K. c. ZElGLE FEED ROLL FOR STAMP VENDING MACHINES 2 Sheets-Sheet 2 Filed Dec. 6, 1954 WAC/V70? Af /wiry C ZF/GLE United States Patent FEED ROLL FOR STAMP VENDING MACHINES Kenneth C. Zeigle, Minneapolis, Minn., assignor to Electric Vendors, Inc., Minneapolis, Minn., a corporation of Minnesota Application December 6, 1954, Serial No. 473,330

3 Claims. (Cl. 271-23) This invention relates to feed rolls. More particular- 1y, it relates to feed rolls of new and improved construction for stamp vending machines and the like.

This application is related to my previously filed application entitled Mold and Method for Making Feed Rolls for Stamp Vending Machines, Serial Number 466,- 350, filed by me on November 2, 1954.

In the manufacture of stamp vending machines and the like, one of the most important parts to be constructed is the feed roll. It is the feed roll which drives or progrosses the stamps through such a machine. Because of its important function it is imperative that the feed roll be very accurately formed else the strip of stamps may be damaged or may become misaligned and/or the machine may become fouled. In prior stamp vending machines the operable feed rolls were prepared through a very laborious, tedious and expensive operation. They generally were made of a metal cylinder into which small holes were bored. Into these small holes metal pegs were secured. Previously the pegs were machined to the desired size and shape insofar as was possible to form the desired teeth required to fit into the openings of the perforated stamp roll to effect the progression of the stamps through the machine. This method of forming the feed rolls is very unsatisfactory in that it is very difficult to manufacture the feed rolls according to specifications and it is very costly because of the time and labor required.

Various attempts have been made to form these feed rolls by well known casting methods, but the teeth on these feeds rolls are necessarily of such small size both in diameter and length that such attempts have been un successful. The air trapped in each tooth-forming recess would prevent the formation of accurate and uniform teeth with the result that the manufactures have had to return to the old tedious and expensive method of placing pegs'into drilled holes after machining them to the desired shape and size. My invention is directed toward solving these problems.

It is a general object of my invention to provide a novel and improved feed roll for stamp vending machines and the like of simple and inexpensive construction and operation.

A more specific object is to provide a novel and improved feed roll for stamp vending machines and the like, the feed roll having its teeth molded in situ and integrally with its stamp supporting surface.

Another object is to provide a novel and improved feed roll for stamp vending machines and the like wherein the. main body portion of the roll and the teeth thereon are formed simultaneously and in a single operation.

Another object is to provide a novel and improved method and mold for producing feed rolls for stamp vending machines and the like which will produce such feed rolls without having to set each tooth therein sepa-, rately and without having to form each tooth separately from the main body of the roll.

Another object is to provide a novel and improved method and mold for forming feed rolls for stamp vending machines and the like which will produce a feed roll in substantially less time and with less labor and hence much more economically.

These and other objects and advantages of my invention will more fully appear from the following description made in connection with the accompanying drawings, wherein like reference characters refer to the same or similar parts throughout the several views and in which:

Fig. 1 is a fragmentary side elevational view of a stamp vending machine having one embodiment of my invention mounted therein for rotation to progress the stamps through the stamp vending machine.

Fig. 2 is a vertical sectional view of my mold designed to construct my improved feed roll, with the closure member detached therefrom shown in broken lines.

Fig. 3 is a top plan view of the mold with the closure member removed from the base member and with a feed roll formed therein.

Fig. 4 is a plan view of the inner surface of the closure member which registers with the base member of the mold when secured thereto.

Fig. 5 is a side elevational view of my novel feed roll as it leaves the mold with a portion thereof shown in section.

Fig. 6 is a side elevational view of the completed feed roll after it has had the grooves cut into the cylinder, and after the driving gear has been secured thereto.

Fig. 7 is an end elevational view taken along line 7-7 of Fig. 6.

Fig. 8 is a fragmentary end elevational view of one of the feed rolls on an enlarged scale showing the detail of one of the teeth of the feed roll.

Fig. 1 shows a feed roll constructed in accordance with my invention mounted for rotation in a stamp vending machine indicated generally as M and supported by the frame 10 thereof so as to extend transversely of the direction of movement of the stamps 11 as they unroll from the stamp roll 12. The stamps are progressed through the machine by the feed roll 13 which is actuated by a solenoid 14 through connecting linkage 15. It will be noted that the stamps 11 pass around the circumferential surface of the feed roll 13 and between the roll and the stamp guides 16, the teeth 17 of the feed roll extending through the perforations between the individual stamps and thereby engaging the stamp strip to cause the stamps to progress through the machine. Important details of such a stamp vending machine other than the feed roll 13 can be seen by reference to a related application Of which I am co-inventor and entitled Stamp Vending Machine, Serial Number 447,766, filed August 4, 1954. To form the stamp feed roll I have provided a novel mold indicated generally as O in Fig. 2 and comprised of a base member B and a cover or closure member 18. The cover or closure member, as best shown in Fig. 4, has a sprue hole 19 formed therein which connects the central portion of the mold which is the cavity thereof, as will be hereinafter described, with the exterior. A pinreceiving opening 20 is formed at the central portion of the closure member 18 and is defined by a bearing 21 which is adapted to receive a central pin therein in tightfitting relationship. A pair of alignment pins 22 and 23 extend inwardly from the inner surface of the closure member so as to properly align the closure member with the base member B when the two members are brought together and secured to each other in any of the conventional manners in pressure molding.

The base member B has a recess 24 formed therein and positioned contrally thereof. When the closure member 18 is secured to the base member B, this recess becomes a closed compartment. The recess 24 is tapered downwardly, as best shown in Fig. 2. Alignment holes H adapted to receive the alignment pins 22 and 23 are provided in the recess-defining portions of the base member B. The base member has a central pinreceiving opening which extends therethrough axially of the recess 24. Slidably mounted in this opening is an insert-receiving pin 26 which extends upwardly into the recess 24. Four stripper bolt passages such as 27 and 28 are arranged around the pin-receiving opening 25 and extend through the base member parallel to the tapered walls of the recess 24. As can best be seen in Fig. 2, these recesses extend upwardly in diverging relation into the peripheral portions of the bottom of the recess. Slidably mounted in each of these passages, such as 27 and 28, is a stripper bolt such as 29 and 30.

Mounted on each of the stripper bolts such as 29, 30 is one of four matrix sections 31, 32, 33 and 34, which fit within the recess 24 and cooperatively define a cylindrical cavity 35 therebetween in conjunction with the base member B and the closure member 18, the axis of the cavity being the same as the longitudinal axis of the pin 26. Each of the matrix sections has opposite side surfaces such as 31a and 31b which register in tight-fitting relationship with one of the side surfaces of the adjacent matrix section to form a break line 36 therebetween. Each of these side surfaces such as 31a and 31b is flat and smoothly polished so as to perfect a substantial seal with its adjacent surface so that material forced into the cavity 35 cannot pass outwardly therebetween in any substantial amount. Each of the matrix sections 31, 32, 33 and 34 tapers at the bottom, as best shown in of this mold are not at the break line as is usual in forming teeth on a cylindrical surface, but on the contrary are positioned midway between the break lines 36. This is contrary to conventional molding. If the recesses 37 were positioned at the break lines, a web would form between the teeth so that the entire structure would be unsatisfactory. It is necessarythat these recesses be positioned at points other than the break line in order to form a satisfactory end product. i 7

After the hot white nylon has been forced into the mold as described above, the closure member 18 is removed and the stripper bolts such as 29 and and the insert-receiving pin 26 are forced outwardly so as to move the matrix sections 31, 32, 33 and 34 from the recess 24. As these matrix sections move toward the right, as viewed in Fig. 2, they move both axially and radially outwardly relative to the cavity so that they will separateand the molded cylindrical feed roll will be suspended by the reduced end portion of the insertreceiving pin 26. The molded feed roll may then be quickly and easily withdrawn from the free and reduced end of the insert-receiving pin 26 and it is ready for the finishing steps to be hereinafter described. For practical purposes, however, the feed roll at this point has been end plate 41 pressed into the open end thereof. This end Fig. 2, and the outer arcuate surface thereof confonns to the curvature of the recess 24 so that when the closure member 18 is secured to the base member B, the four matrix sections fit snugly together and fill the more peripheral portions of the recess 24 and leave only the cylindrical cavity 35 therebetween.

Each of the matrix sections 31, 32, 33 and 34 has a plurality of spaced teeth-forming recesses such as,37 formed in the cavity-defining surfaces thereof. As best shown in Figs. 2 and 3, these recesses are arranged in spaced groups of three along lines parallel to the axis of the cylindrical cavity and are positioned midway between the fiat side surfaces such as 31:: and31b. Each of the recesses tapers radially outwardly toward a point and is conical in shape. Each has a magnitude of approximately .047 inch in depth and .032 inch in diameter.

To form the feed roll the closure member 18 is removed from the base member B of the mold and a hollow cylindrically shaped metal insert is placed around the insertreceiving pin 26 within the cavity 35. This insert 38 is preferably of a light metal such as aluminum and has an opening 39 at one end which snugly fits around the reduced portion of the insert-receiving pin, as best shown in Fig. 2. The other end of the insert remains open so that the bearing 21 carried by the closure member 18 extends thereinto to snugly hold the insert in proper place. The outer cylindrical surface of the insert 38 is knurled. 7

After the insert has been positionedas described above, hot white nylon is forced into the sprue hole 19 under substantial pressure. This hot white nylon is one of the polyamides currently being manufactured and widely sold on the market. This particular polyam ide is unusually hard and wears very well. Thiswhite nylon isinjected through the sprue hole at a temperature .of approximately 525 degrees Fahrenheit'and at pressures of approximately 1,200 psi. The mold O is permitted to remain at room temperature.

It will be noted that the sprue hole 19 connects the exterior with the space. between the surfaces defining the cavity 35 and the exterior of the insert 38 so that the white nylon is forced into this openarea and into the minute recesses 37. It will be noted thatthe recesses plate has a central opening therein which merely serves as a bearing for the mounting pin 42, as shown in Fig. 1, which rotatably mounts the feed roll when it is in use The feed roll 40 is then ready, if desired, for use in a stamp vending machine. If, however, it is desired to provide automatic means for cutting off the current to the vending machine as disclosed and claimed in the'application hereinbefore referred to, then the grooves 44a and 44b may be cut by a lathe into the cylindrical segment 44 of white nylon which has been molded onto the exterior surface of the insert. It will be noted that the grooves 44a and 44b are positioned between-the groups of teeth 45 which were formed by the recesses 37. To drive the feed roll, a drive gear 46 may be secured to one end thereof by pins such as 46a. The details of construction of this drive gear are also disclosed in the application hereinbefore referred to. It will be noted that the resulting feed roll is a cylinder adapted to be mounted for rotation in a stamp vending machine for rotation about its axis while positioned transversely of the direction the stamps move. The white nylon cylinder 44 has a plurality of teeth 45 molded in situ integrally with the cylinder 44 and these teeth are arranged in rows along a line parallel to the axis of rotation ofthecylin der. As best shown in Fig. 1, they are spaced trans versely of the stamps and they engage the openings of these stamps to progress the same through the machine. As best shown in Fig. 6, the teeth 45 are spacedcircumferentially of the cylinder 44.

i Fig. 8 shows a detailed view of one of the teeth 45.

There is a radius of curvature of inch adjacent the point of the tooth as at 47. The length of the tooth from the cylinder out to its point is .047 inch and the diameter of the tooth at its base is .032 inch. The radius of curvature at the point where the tooth leaves the circumferential surface of the cylinder 44 as at 48 is .005

escapes be noted that the teeth are molded integrally with the cylinder in my novel feed roll and that a substantial reduction in cost and time required is thereby effected. At the same time white nylon is considerably cheaper than metal and thus the cost of the materials required to manufacture my feed roll is substantially less.

It will be noted that the outer end portions of the teeth of my feed roll are curved. These outer end portions of the teeth 45 have a radius of curvature of A of an inch while the radius of the nylon cylinder is .97 inch. The other end portions of these teeth are accurately curved with this radius of curvature to facilitate the engagement and disengagement of the stamp strip by these teeth. By so curving the end portions of these teeth, I am able to prevent the tearing of the paper of the stamps during their engagement and disengagement by these teeth as the stamps are progressed thereby through the vending machine.

Another advantage of my novel and improved feed roll, of course, is that the cylinder and the teeth of my feed roll may be formed simultaneously and in a single operation. Both are molded at one and the same time and their formation can be accomplished very quickly.

It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the various parts without departing from the scope of my invention.

What is claimed is:

l. A feed roll for postage stamp vending machines and the like for feeding strips of postage stamps having aligned perforations therein closely approximating .032 inch in diameter, said feed roll comprising a molded white nylon cylinder adapted to be mounted within the machine for rotation about an axis transverse to the direction of movement of the stamps within the machine, and a plurality of equi-distantly, circumferentially spaced rows of white nylon teeth molded integrally with said cylinder and extending radially outwardly from the circumferential surface thereof along lines extending parallel to the axis of rotation of said cylinder, and said teeth being conical in shape and of the order of magnitude of size of .03 inch in diameter and .05 inch in length.

2. A feed roll for postage stamp vending machines and the like for feeding strips of postage stamps having aligned perforations therein closely approximating .032 inch in diameter, said feed roll comprising a rotary metal 6 core adapted to be mounted for rotation within the machine about an axis transverse to the direction of movement within the machine, a cylindrical segment of white nylon molded onto said core member in encircling relation, and a plurality of spaced white nylon teeth molded integrally with the circumferential surface of said cylindrical segment and extending radially outwardly therefrom and arranged along a plurality of circumferentially spaced lines extending parallel to the axis of rotation of said core, said teeth being conical in shape and of the order of magnitude in size of .03 inch in diameter at their base and .05 inch in length.

3. A feed roll for postage stamp vending machines and the like for feeding strips of postage stamps having aligned perforations therein closely approximating .032 inch in diameter, said feed roll comprising a cylinder molded of white nylon and adapted to be mounted within the machine for rotation about an axis transverse to the direction of movement of the stamps within the machine, and a plurality of rows of spaced white nylon teeth molded integrally with said cylinder and extending radially outwardly from the circumferential surface thereof and arranged along a plurality of circumferentially spaced lines extending parallel to the axis of rotation of said cylinder, said teeth being generally conical in shape and having curved lateral surfaces with a radius of curvature approximating ,4 inch, said teeth being of the order of magnitude in size of .03 inch in diameter at their base and .05 inch in length.

OTHER REFERENCES Publication: General Electric Review, July 1952, vol.

Reference A (Advertising on page 37, Plastic World Magazine), August 1953. 

